A bomb targeting Syria’s military leadership killed the country’s defense minister Wednesday and at least two other high-ranking officials, sparking questions about how long the besieged government of President Bashar Assad can remain in power and highlighting the differences between the United States and Russia over what steps should be taken to curb the violence that’s sweeping Syria.

Syrians celebrate after hearing about the suicide attack that hit the National Security building in Idlib.
Shaam News Network/AP

A bomb targeting Syria’s military leadership killed the country’s defense minister Wednesday and at least two other high-ranking officials, sparking questions about how long the besieged government of President Bashar Assad can remain in power and highlighting the differences between the United States and Russia over what steps should be taken to curb the violence that’s sweeping Syria.

The deaths of Defense Minister Dawoud Rajha, his deputy, Assef Shawkat, who was Assad’s brother-in-law, and Hassan Turkmani, a former defense minister, marked the first time the rebels who are fighting to topple Assad have managed to kill members of his inner circle. According to Syrian state media, the blast also wounded Interior Minister Mohammed Shaar.

Rebels said the men were part of Assad’s “crisis management” team, which met daily at different locations throughout the capital. Rebels have been targeting the group for months. In May, the rebels claimed to have killed Shawkat by poisoning him.

U.N. Syria envoy Kofi Annan, who’s been struggling to impose a peace plan on Syria’s warring factions, condemned the bombing, as did Russian Foreign Minister Sergey Lavrov. The Obama administration declined to do so, instead repeating its call for Assad to step aside. “It is precisely because of the ongoing campaign by President Assad against his own people that we are seeing a situation that is getting worse and worse,” White House spokesman Jay Carney said.

In some of Damascus’ northern suburbs, fighters reacted to the news with unrestrained glee, breaking into spontaneous song and repeatedly shouting, “God is great.” But by nightfall there were reports in parts of the city that pro-government fighters were taking revenge against residents of neighborhoods that support the rebels.

Fighting raged in parts of Damascus throughout the day, though the threat to the government from that violence was unclear. For the first time since the uprising against Assad began 16 months ago, Syrian government forces began shelling rebels in the city proper over the weekend. But the areas where the fighting is taking place are largely the same ones that previously have been the scene of violence and where militancy has been heightened in recent months by an influx of refugees from Homs and other conflict areas who openly support the rebellion.

“The consequences of what happened today are not clear,” said Radwan Ziadeh, an anti-government activist who’s focused on documenting civilian and rebel casualties during the conflict. “But I don’t think Bashar Assad can control Damascus anymore.”

Residents of the city reported attacks by the military after the blasts.

“They are shelling my street,” said a resident of Yarmouk, in southern Damascus, who spoke by telephone only on the condition that he not be identified, for fear of government retribution. “I asked my parents to leave three days ago, but I don’t know what has happened to my uncles.”

“There are many tanks coming into Yarmouk. Mosques are being turned into field hospitals. There are a lot of refugees coming from al Hajar, al Tadamon,” another Yarmouk resident, said, referring to adjacent neighborhoods where fighting was taking place.

“They are staying in the schools,” said the man, who also asked not to be named, referring to the refugees. “There is no place to go.”

The Syrian government moved quickly to stanch claims that the bombing had crippled its security apparatus. It named Fahd Jessem al Freij the new minister of defense within hours of the attacks. Freij made a statement Wednesday promising to continue the fight against “terrorist gangs,” the government’s catchall term for the opposition.

Speaking from his headquarters in southern Turkey, Free Syrian Army commander Riad al Asaad claimed responsibility for the day’s attacks. The Free Syrian Army is the moniker the majority of the rebels use, but it was unclear whether the attacks were part of a larger coordinated rebel offensive or the result of independent initiatives by local rebel commanders in Damascus.

In February and March, assaults by government troops pushed rebels out of a number of urban areas that they’d seized. But since April, the momentum appears to be in their favor as they’ve secured routes for weapons trafficking and apparently solved funding problems. Rebels have made inroads recently into areas of the cities of Deir el-Zour and Idlib they’d been kicked out of in March. A recent study by the Washington-based Institute for the Study of War found that rebel attacks on government positions surged in April and May, when a U.N.-sponsored cease-fire was supposedly in effect.

Wednesday’s bombing drew an immediate international response. The U.N. Security Council postponed a vote scheduled for Wednesday on a resolution to extend the mandate of the U.N. mission that’s in Syria to monitor the progress of the peace plan. The mandate expires Friday.

Israeli Defense Minister Ehud Barak announced that he’d summoned his top security and intelligence advisers to a meeting to discuss the situation, a move all the more startling because Israel has tried to remain publically aloof from the events unfolding in its neighbor to the north. In recent days, however, Israeli officials have expressed concern that the deteriorating situation in Syria could lead to a number of dangerous scenarios. In a parliamentary meeting Tuesday, Israel’s head of military intelligence said there was concern that Syria’s chemical weapons could fall into rogue hands, especially as the presence of foreign jihadist groups in Syria increased.

President Barack Obama spoke with Russian President Vladimir Putin but apparently failed to resolve the differences between the countries over how best to end the violence in Syria.

In comments, U.S. Defense Secretary Leon Panetta underscored the American position that no peace is possible with Assad still in office. “It is more essential than ever that the United States and the international community continue to work together, through the United Nations, through whatever possible vehicles we have, to bring additional pressure on Assad to step down and to allow for a peaceful transition of government there in Syria,” he said.

In response to the intensified fighting in the capital, the Syrian army appeared to have cut major arteries in and out of the city. Rebel fighters in al Tal and in the northern suburb of Rancous spent much of the day searching for routes into the capital in hopes of joining the fighting there, but they said the presence of Syrian army units stymied them.

Elsewhere, rebels predicted that the bombing would lead to more anti-government attacks. One rebel commander reached by phone in Idlib province in the country’s north said rebel units in the area had received no prior indication of the attack or further orders from higher Free Syrian Army command. But he thought that the intensified fighting in the capital was a signal to rebel units throughout the country.

“This is what we have been waiting for. We have our own attack here. It will be so big and we will do it so soon,” said the commander, who asked to remain anonymous out of concerns about government retaliation.

Rebel fighters repeatedly have expressed their belief that the real fight for the country will occur in Damascus. Many have said they expect a renewed offensive to coincide with the Muslim holy month of Ramadan, which begins later this week.

But it was clear also that the government hadn’t lost its ability to launch attacks. Earlier in the day, a rebel safe house in the usually peaceful Damascus suburb of Yabrud was hit by artillery or rocket fire, resulting in the deaths of five rebels. Ten rebels were wounded. It was the deadliest attack in Yabrud since the beginning of the conflict.

Reached via phone, a local rebel fighter suspected that the rebels may have been targeted by their cellphone signals. He expressed concern that the group might have a government collaborator within its ranks.

The funeral for the slain rebels drew thousands of demonstrators into the streets.

There were also reports of unexpected calm. An activist near the flash-point city of Homs said an eerie quiet had descended on the city, and that on Wednesday residents had heard no sounds of the shelling that had become part of their daily lives.

Nancy A. Youssef in Cairo, Matthew Schofield and Hannah Allam in Washington and special correspondent Sheera Frenkel in Jerusalem contributed to this article.